TITLE:
In Vitro Screening and Selection of Probiotic Lactic Acid Bacteria Isolated from Spontaneously Fermenting Kunu-Zaki
AUTHORS:
Solakunmi Omotunde Oluwajoba, Felix Akinsola Akinyosoye, Victor Olusegun Oyetayo
KEYWORDS:
Probiotic; Spontaneously Fermenting; Germination; Composite; Non Composite
JOURNAL NAME:
Advances in Microbiology,
Vol.3 No.4,
July
18,
2013
ABSTRACT: The
present study was conducted to determine the pro-biotic properties in vitro of the lactic acid bacteria
isolated from spontaneously fermenting kunu-zaki. Kunu-zaki was processed using
composite, non composite, germinated and ungerminated Digitaria exilis (Fonio), Sorghum bicolor (Sorghum) and Pennisetum
americanum (Millet) cereals. A total of 150 LAB isolates were obtained from
all the fermenting slurries. These 150 LAB isolates were screened for their
ability to grow at pH 3.0, resistance against bile salt and ability to inhibit
reference test pathogens. Out of these 150 LAB isolates; 21 exhibited good
probiotic properties. All the 21 isolates were further identified to specie and
subspecies level using standard API50CHL system with all 21 showing good
survival (P Lactobacillus species, 2 Pediococcus species and 1 Lactococcus specie. These LAB species
were further examined for antimicrobial activity against the growth of
reference pathogens Staphylococcus aureus 25923, Escherichia coli 25922, Pseudomonas aeruginosa 27853 and Enterococcus faecalis 29212. All 21 LAB
species exhibited good inhibition of all test reference pathogens except Lactobacillus fructivorans, Lactococcus lactis sp lactis and L. fermentum which however, showed no
zone of inhibition against the growth of E.
faecalis. Kunu-zaki made from composite un-germinated Sorghum bicolor (Sorghum) and Pennisetum
americanum (Millet) cereal grains contained the highest percentage (52%) of
LAB species which showed good probiotic criteria in vitro. Non composite ungerminated cereals accounted for 33% of
the total probiotic LAB isolates whilst the germinated non composite and
composite cereals recorded the lowest percentage (10%) and (5%) of probiotic LAB
respectively. The results of this research study showed that the LAB species
isolated from wild fermentation of kunu-zaki beverage fulfilled the criteria
for in vitro screening of probiotic
characteristics. These LAB species possed potential for further use as
probiotic in human preparations and suggested the use of kunu-zaki made from
ungerminated composite sorghum and millet grains as a natural probiotic drink.